I'd rather have my kids on a surface lift, all things considered. But the other points here are fair, particularly no. 3.
A chair also allows you to serve terrain that might only have snow at the top, or even none at all (eg, off the chair, onto the next one, skis in hands, etc.).
Our back bowls were served by two T-bars when I arrived in Italy 17 years ago, and they were soon replaced by a slow chair. Given that a high-speed lift is not in the cards, I'd take the T-bars back in a second, MUCH warmer ride (and you can get off early if you want).
(Actually I'm drawing a blank on whether they were T-bars or Pomas. Mr. Nobody?).